1. Field of the Invention
The invention relates to an apparatus for metering powdered filling material and more particularly for dispensing such materials for filling capsules or the like.
2. Description of the Prior Art
One known apparatus of the type with which this invention is concerned is disclosed in DE 31 10 483 A1 which describes the apparatus as including the provision that adjusting means are used to press the stop ring against the underside of the metering disk. No further details of this are given. The stop ring is pressed against the underside of the metering disk in order to prevent powder from escaping from the through openings into the gap between the underside of the metering disk and the stop ring during the insertion of the tamping plungers into the openings of the metering disk. Such powder losses are undesirable first, because the escaping powder contaminates the apparatus, and second because the powder loss represents a not so insignificant cost factor, particularly with relatively costly pharmaceuticals. It would therefore be desirable to produce an apparatus that prevents powder losses during insertion of the tamping plungers into the openings of the filling material container; the apparatus should function with a high degree of operational reliability and should at the same time also be relatively simple in design.
The apparatus for metering powdered filling material according to the invention has the advantage that it functions in a particularly operationally reliable and low-friction manner due to the spring means, which hold the metering disk a definite distance away from the stop ring during its rotation, and that it is also relatively simple in design due to the stationary disposition of the stop ring, which consequently does not require any moving mechanism.
Other advantageous modifications of the apparatus for metering powdered filling material according to the invention are disclosed. A structurally simple, advantageous embodiment of the relative mobility between the metering disk and the stop ring is achieved by virtue of the fact that the filling material container has a central region and an outer region, which are connected to each other in such a way that they do not rotate in relation to each other, but can be moved axially in relation to each other. Preferably this embodiment is covered by an elastic covering element in the filling material container, which prevents powder from getting into the transition region between the central region and the outer region of the filling material container.
A compact embodiment of the invention can be achieved if the spring means, which hold the metering disk spaced apart from the stop ring, are integral to the axle journal that drives the metering disk.
In a preferred embodiment, the filling material container is pressed down against the stop ring by means of a rib, which is situated outside the boundary wall of the filling material container. This prevents the mechanism for pressing down the filling material container from coming into contact with the filling material contained in the filling material container.
The press-down mechanism for the filling material container can be embodied in a simple way if it is attached to a support on which the tamping plungers are also disposed. As a result, the press-down element, which presses the filling material container against the stop ring, is automatically moved along with the downward motion of the tamping plungers.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings, in which the sole figure shows a simplified longitudinal section through an apparatus according to the invention for metering powdered filling material.